[PATCH net-next v2] net: make sure we never create ifindex = 0

[PATCH net-next v2] net: make sure we never create ifindex = 0

[Jakub Kicinski]

Instead of allocating from 1 use proper xa_init flag,
to protect ourselves from IDs wrapping back to 0.

Fixes: 759ab1edb56c ("net: store netdevs in an xarray")
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: leon@kernel.org
---
 net/core/dev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index b58674774a57..10e5a036c706 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -11271,8 +11271,7 @@ static int __net_init netdev_init(struct net *net)
 	if (net->dev_index_head == NULL)
 		goto err_idx;
 
-	net->ifindex = 1;
-	xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC);
+	xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1);
 
 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
 
-- 
2.41.0

Re: [PATCH net-next v2] net: make sure we never create ifindex = 0

[Leon Romanovsky]

On Mon, Jul 31, 2023 at 10:11:58AM -0700, Jakub Kicinski wrote:
> Instead of allocating from 1 use proper xa_init flag,
> to protect ourselves from IDs wrapping back to 0.
> 
> Fixes: 759ab1edb56c ("net: store netdevs in an xarray")
> Reported-by: Stephen Hemminger <stephen@networkplumber.org>
> Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> CC: leon@kernel.org
> ---
>  net/core/dev.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

Re: [PATCH net-next v2] net: make sure we never create ifindex = 0

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 31 Jul 2023 10:11:58 -0700 you wrote:
> Instead of allocating from 1 use proper xa_init flag,
> to protect ourselves from IDs wrapping back to 0.
> 
> Fixes: 759ab1edb56c ("net: store netdevs in an xarray")
> Reported-by: Stephen Hemminger <stephen@networkplumber.org>
> Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: make sure we never create ifindex = 0
    https://git.kernel.org/netdev/net-next/c/ceaac91dcd06

You are awesome, thank you!
-- 
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